Method of making tubular bodies



July 110 ,1923.

P.A.E.ARMSTRONG METHOD OF MAKING TUBULAR BODIES Filed Febv 1919 7 INVENTOR /fiERNEY Elli l etented duly 11%, W23.

PEEGY A. E. A P51 M STRONG, F LOUDQNVILLE, new YQBZ.

mnon or MAKING renounce n rms.

Application tiled lFebruary 3, 1919. Serial lfllo. $745535.

To all whomt may concern:

Be it mown that I, Pnncr A. E. Amus'rnouc, a subject of the King of Great Britain, and a resident of Loudonville, county of Albany, and State of New York, have invented certain new and useful Imrovements in Methods of Making Tubular odies, of which the following is a specification.

This invention relates to an improved process of making tubular bodies such as hollow drill rod and the like.

Heretofore in making such tubular members a billet has been provided with a. longitudinal bore, as by drilling, and after the bore has been formed a. core has been introduced into said bore and the billet and core elon ated and reduced in cross-section, as by rolling, and the core removed.

According to the present invention the core is laced within an ingot mold and the materiel from which the elongated tubular body is to be formed, as steel in the case of making hollow drill rod, is introduced therein around the core while in molten state, and when it has solidified with the core in place therein the in t and core are subgected totreatment or elongation and reduction of crom-section, as b rolling, after which the coreis oved, caving the tubulor body desired to be produce The ingot, with the core in place therein, may be rolled before being cooled down from its casting heat to below rolling temrature, or it may be further cooled and reented for rollingyas will be readily understood.

Corm of various kinds may be used, so long as some are adapted for removal after rolling. F or example, the core may be sub stnntially entirely of refractory material, such as finely divided talc, magnesite or other suitable materials which are substantially inzlusible at the temperature employed. In such case the core ends are preferably sealed in place, as by welding over or the like, before rolling; or an all metal core with a surface layer of non-welding material, such as aluminum oxide, lime or the like, may be employed, and various other toe of core may m used and same may be in one part or maybe in two or more parts.

Preferably, a core such as is illustrated in the eccompenying drawing is used, comprisin. a metallic interior member which may, or convenience, be termed a rod, and

an outer substantially thick surrounding layer of refractory material, such as talc, dead burned magnesite or other suitable material which is substantially infusible at the temperatures to which it is subjected. After rolling the drill rod or other tubular body may be cut or broken into coercial lengths, and the core removed either before or after suchdivision into lengths. If the core end projects as shown in the drawing it may conveniently provide a head, after rolling, to fasten to for core pulling, and the other end may be cut or broken oil to remove any malformed portion. The following end of the rod, which is pulled through and comes out last, may be deformed, as by striking with a hammer or other tool, and the battered end may serve for breaking up the layer of refractory material, which can then be readily removed. Pushing may be resorted to for partial or entire removal of the core rod when desired.

In the drawing, F i l is a diagrammatical, longitudinal, sectional view of an ingot mold with a core and an ingot being cast therein. Fig. 2 is a plan view showing a centralizing holder for the core. In said drawing the ingot mold, which may be oil any usual or desired form is represented at 10. The core is represented at 11 and comprises a metallic interior member 12 and a substantially thick surrounding layer 13 of refractory material. It desi. cites the molten material from which t e tubular body is formed, as steel for making hollow drill rod.

The core may be centralized in any desired manner, as by providing a recess or socket 15 to receive the bottom end thereof and by applying suitable holding means to the upper end 16 of the core, or in other ways. In the form shown a crossbar 17 is illustrated for supporting the upper end of the core centrally of the mold. It hasan opening 18 for the core and has an extended base 19 which fits within the mold and serves to centralize the opening 18 and thereby the core. The leg 20 bears against the mold on the side opposite the base 19; By making the supporting member in the form shown. the core may be held stationary in properly centralized position, and at the same time there is ample room for pouring the molten metal in place. Other forms of centralizing means may of course, be used. The cast ingot with the core in place therein,

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llllll after removal from the mold is treated for elongation and reduction of cross-sectional ingot and core, as by rolling or the like operation, and the core removed. \Vhen the core consists of a central rod or the like surrounded with refractory material, the rod is first removed and thereafter the refractory material cleaned out.

It will be seen that among the advantages secured by the process of the present invention are these:

It results in a substantial saving of work, time and material. It entirely dispenses with the formation of the bore in a billet as a separate operational step and with any necessity for fastening the core in place against relative movement after insertion into a previously bored billet. It eliminates any danger of lnjuring the core or its surface, which may be encountered when inserting same into a previously formed billet bore.

It is to be understood, however, that the type of core shown is for illustration only and that cores and weld-preventing materials of various kinds may be resorted to,

50 lon as the ingot is formed by casting aroun the core, and further, that while my invention has been described more particularly in connection with making hollow drill rod, it is applicable to making tubular bodies generally.

I claim:

1. The process of making tubular bodies such as hollow drill rod and the like which consists in casting an ingot around a core, treating the ingot and core for elongation and reduction of cross-section, as by rolling and removing the core;

2. The process of making tubular bodies such as hollow drill rod and the like, which consists in casting an ingot around a core comprising a metal rod and a substantially thick surrounding layer of refractory material, treating the ingot and core for elongation and reduction of cross-section, as by rolling, removing the core rod, and removing the refractory material.

In testimony that I claim the foregoing, I have hereto set my hand, this 31st day of January, 1919.

PERCY A. E. ARMSTRONG. 

